Preparation And Characterization Of Starch-polycaprolactone Composites Compatibilized With Polyester Polyols

The current non-biodegradable plastic waste seriously endanger the human living environment, so it is imperative to prepare low-cost biodegradable polymer materials.Starch-polycaprolactone composites can be biodegraded completely. However,their inherent deficiency is that starch and polycaprolactone (PCL) are incompatible and their mechanical properties are poor. In this paper, polyester polyols with different molecular weights were prepared by microwave method and the starch-polycaprolactone polymer composites were modified with synthetic polyurethane prepolymer using polyester polyol to improve the interfacial compatibility and mechanical properties of the polymer composites. Based on the above exploration, it is promising to synthesize a low-cost polymer composite with excellent performance.First, adipic acid and butanediol with a molar ratio of 1: 1.2 were selected as the monomers of copolymerization reaction in which tetra-n-butyl titanate acted as catalyst in this aticle. Then the white waxy solid was generated under specific conditions with the computer microwave catalytic synthesis of extractor and characterized by liquid nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy (FTIR),which demonstrated that PBA was successfully acquired. Compared with the traditional synthesis method of polyester, this PBA preparation procedure took much less time and had higher security. Subsequently, the low boiling water was distilled by the vaccum distillation, thus increasing the degree of esterification reaction and PBA molecular weights in the meantime. Therefore, polyester polyols with various types and molecular weights can be achieved rapidly, including polyethylene adipate diol, polyhexamethylene adipate diol, polybutylene succinate diol, polybutylene succinate diol (PBS),polybutylene glycol dihexanediol diol, etc.Next, the synthesized hexanediol adipate diol with molecular weight of 1338 was used to react with 4,4'-diphenylmethane diisocyanate (MDI), resulting in the generation of polyurethane prepolymer (PHAPU) in the third chapter. And then PHAPU, starch and polycaprolactone were blended in a internal mixer to prepare a series of composite materials. The composites were kept in the incubator to equilibrate for one day, followed by the fourier transform infrared spectroscopy (FTIR) and the tension test of these different composites. The results showed that the compatibility and mechanical properties of the starch-polycaprolactone composites with different contents of polyester-based polyurethane prepolymers have been improved.